The present invention relates to internal combustion engines in general, and more particularly to improvements in apparatus for saving energy during operation of internal combustion engines. Still more particularly, the invention relates to improvements in apparatus for coupling a second crankshaft to, or for disconnecting the second crankshaft from, a first crankshaft in order to save fuel for operation of internal combustion engines.
It is already known to save fuel by disconnecting one or more cylinders of a multi-cylinder internal combustion engine when the engine is to operate at partial load. For example, German Offenlegungsschrift No. 28 28 298 discloses a method of operating an internal combustion engine which has several cylinders installed in a common block. The engine further comprises several crankshafts including a first crankshaft in a first engine section embodying a first group of cylinders and a second crankshaft in a second engine section embodying a second (e.g., the remaining) group of cylinders. When the engine is operated at partial load, the second group of cylinders is deactivated by disengaging the corresponding (second) crankshaft from the other (first) crankshaft. In order to restart the temporarily deactivated section, the second crankshaft must be coupled to the first crankshaft in such a way that the two crankshafts will be maintained in predetermined angular positions with reference to each other to thereby ensure firing of the cylinders in proper sequence.